With the advancement in portable electronic devices and intense interest in plug-in hybrid electric vehicles, there is great demand to increase the energy and power capabilities of lithium ion batteries. In this regard, increasing the operational voltage is a viable strategy. Current lithium ion battery electrolyte solvents typically contain one or more linear carbonates, such as ethyl methyl carbonate, dimethyl carbonate, or diethyl carbonate; and a carbonate, such as ethylene carbonate. However, at cathode potentials above 4.2 V these electrolyte can decompose, which can result in a loss of battery performance. What is needed is a formulation that combines solvent(s) with additive(s) that will have improved cycling performance at high temperature when used in a lithium ion battery, particularly such a battery that operates with a high potential cathode.